Recent years, imaging devices for still cameras, video cameras and the like have been increasingly automated, and cameras each including an automatic exposure adjusting mechanism, an automatic focus adjusting mechanism and the like are widely in practical use. As a trend toward developing multi-function cameras, several techniques have been also in practical use for implementing a compensating function for compensating an image blur which occurs due to shake of the camera as a whole.
In general, an image blur preventing apparatus including a compensating function is provided with a shake detecting device, an optical compensating device, a driving device, a controlling device, and a holding device. The shake detecting device detects shake of the apparatus as a whole. The optical compensating device compensates an image blur which occurs due to the apparatus shake. The driving device drives the optical compensating device. The controlling device controls the driving device by calculating an amount of compensation of the image blur depending on an output from the shake detecting device. The holding device mechanically holds the optical compensating device in a predetermined position.
For example, Japanese Patent Application Publication No. 2001-066655 discloses that, first, an amount of shake of an imaging apparatus due to the apparatus shake is detected. Then, an amount of displacement of a substrate including a photoelectric converting device is detected while the substrate including the photoelectric converting device is being displaced in response to the detected amount of shake. The amount of shake is compensated in response to the detected amount of displacement, and thus the substrate including the photoelectric converting device is displaced, and thereby, the apparatus shake is compensated.
Japanese Registration Patent No. 3188739 discloses that an imaging apparatus is provided with a mechanical holding device and an electrical holding device. The mechanical holding device mechanically holds an optical compensating device in a predetermined position. The electrical holding device is designed to operate when the mechanical holding device is converted from one state to another state, and holds the optical compensating device in a predetermined position. When the mechanical holding device is converted to a state in which the mechanical holding device holds the optical compensating device, the electrical holding device is operated so that the mechanical holding device is possible to hold the optical compensating device. In addition, when the mechanical holding device is converted to a state in which the mechanical holding device releases the optical compensating device from being held thereby, the electrical holding device is operated so that the mechanical holding device causes the optical compensating device not to move from the predetermined position.
In this respect, in the electrical holding state, the optical compensating device may be continuously held in the predetermined position while the driving device is being electrified. The mechanical holding device may continuously hold the optical compensating device in the predetermined position even though the driving device is not electrified. It is to be noted that the mechanical holding device includes not only a mechanical holding device involving no electrical control at all, but also a mechanical holding device involving an electrical control when the mechanical holding device is converted to the state in which the mechanical holding device holds the optical compensating device in the predetermined position, or when the mechanical holding device is converted to the state in which the mechanical holding device releases the optical compensating device from being held thereby.